Autogiro rotor hub



AUTOGIRO KOTOR HUB Filed Max-sh 1, 1957 5 Sheets-sheet 1 ATTORNEY.

June 27, 1939.

AUTOGIRO ROTOR HUB l c;4 s. scHAlRER 2,163,893

' 'Filed March 1, 1957 s-sheets-sheet 2 NVENTOR.

-.l-j 3 v 650. 5mg/ff? ATTORNEY.

Filed Marh 1, 1937 5 sheets-sheet 3 INVENTOR.

` ATTORNEY.

Jule 27, 1939. G s, SCH'ARER 2,163,893

AUToGIRo KOTORY HUB Filed March l, 1957 5 Sheets-Sheet 4 INVENTOR. 650. 5 50M/@fe ATTORNEY.

June 27, 1939.- G. 5 SCHAlRER 2,163,893

AUTOGIRO ROTOR HUB Filed March l, 1937 5 Sheets-Sheet 5 INVENTOR. 650. 5 56,1%/659 BY /Z/M ATTORNEY.

Patented June 27, u '1939 PATENT orrics AUTOGIBO KOTOR HUB George S. Schairer, South Bend,A Ind., assigner to Bendix Products Corporation, South Bend,

Ind., a corporation of In Application Mai-ch 1, 1931, serial No. 123,39 1s' claims. (ci. 2li-1s) This inventionrelates to aircraft and more particularly to rotor hubs for rotary winged aircraft.

Irl-the use of rotary winged "aircraft it is de- 5 sirable to control the angle of incidence of the rotating wings in suoli a manner-that the .angle of incidence of the rotating wings may be varied simultaneously and identically while the wings are rotating.

1.0 It is desirable that the angle of incidence of the rotating wings may be decreased while the aircraft is on the ground to permit of the storing of sufficient energy in the wings to permit a rapid or generally substantially vertical take-olf.

When the rotating wings have been speeded up to a rotational speed consistent with storing sufflcient energy-to effect the desired take-off, it is desirable that the angle of incidence of the wings be increased to a maximum operating angle considerably higher than the normal operating angle to effect the take-off. When the aircraft has reached a desired altitude, and the energy stored in the rotating wings has been partially dissipated, it is desirable to progressively decrease the angle of incidence of the wings to a normal oper-` ating angle. .To obtain best results it is, of course, desirable that the angles of incidence of all of l the wings be equal at all times to insure that each of the wings 'will exert equal lifting force.

An object of this invention is therefore to provide a hub for a rotary winged aircraft wherein the angles of incidence of each of the rotating wings may be varied simultaneously and by equal amounts.

A further object is to provide means for varying the angles of incidence of the rotating wings of rotary winged aircraft by rotating two sets of blade supportingraces with respect to each other.

Another object of the invention is to provide a novel two-part hub having blade anchoring means including curved raceways carried by each part of the hub.

A still further object of the invention is to provide manually operable means to decrease the angle of incidence of the rotating wings to substantially zero to permit the storing of energy in the rotating wings preparatory to take-oft. means to increase the angles' of incidence of the wings to a point considerably above the normal operating angles to eect a jumptake-oif, and means to slowly progressively decrease the angles of incidence to the normal operating angles.

Another object is to provide speed responsive means to prevent the angles of incidence of the rotating wif-gs from decreasing below the normal operating angles while the aircraft is in flight. l Yet afurther object of the invention is to providemanually operable means to increase the angles of incidence of the rotating wings to a 5 point considerably above the normal operating angles to obtain a braking action during a substantially vertical descent.

Another object of the inventionv is to provide a resiliently -mounted pylon between the fuselage l and wingsl of a rotary winged aircraft, operably connected to the rotary wing angle lof incidence Ycontrol means to vary the angles of incidence of the rotating wings when the aircraft is subjected to unusual forceswhile in ight.

A still further object of the invention is to provide anti-friction means to permit vertical articulation of the rotating wings .of rotary winged aircraft about the center of the hub.

Yet a further object is to provide novel control 20 means tosteer a rotary winged aircraft.

Another object of the invention is to provide means to tilt the rotating wings of rotary winged aircraft about the center of the hub to steer the aircraft. 25

A further object of the invention is to provide a hub for a rotary winged aircraft having yielding means urging the wings toward a high angle of 4incidence position, and manually releasable locking means to hold the wings in a low angle of incidence position.

Other objects and advantages of this invention will be apparent from the following detailed description of two illustrative embodiments thereof, considered in connection with the accompanying drawings, submitted for purposes of illustration only and not intended to define theiscope of the invention, reference being had for that purpose to the subjoinedclaims. A

In the drawings, wherein similar reference 40 characters refer to similar parts throughout the several views:

Figure 1 is a vertical section of a hub for a rotary winged aircraft'embodying the present invention; 45

Figure 2 is a viewtaken substantially on theY line 2-2 of Figure l;

Figure 3 is a plan view, partly in section, of the hub shown in Figure 1 with the upper shell member removed; 50

Figure 4 is a view similar to Figure 1 showing a modified form of the invention;

Figure 5 is a vertical section of a resiliently mounted pylon designed to be positioned between the fuselage and rotating wings of rotary winged 55 aircraft to iniluence the control of the angles of incidence of the rotating wings;

Figure 6 is a plan view of the hub shown in Figure 4;

' Figure 7 is a side elevation of a resilient member adapted to interconnect two sections of the hub;

Figure 8 is a view taken on the line 8-8 of Figure 6 of a modified form of resilient member;

Figure 9 is a view taken on the line 9-9 of Figure 6 showing a still further modified form of resilient member; A

Figure 10 is a sectional view taken on the line III- I0 of Figure 6;

`Figure 11 is an inside diagrammatic layout view of the wing angle of incidence control mechanism shown in Figure 4;

Figure 12 is a sectional view of a portion of the control mechanism for varying the angle between the rotating wings and the fuselage of a rotary winged aircraft;

Figure 13 is a diagrammatic view of the control mechanism shown in Figure 12 with the mechanism shown in the neutral position;

Figure 14 is a view similar to Figure 13 with the mechanism shown in one extreme operating position; and

Figure 15 is another view, similar to Figure 13, with the mechanism shown in another extreme operating position.

Referring more particularly to Figures 1 to 3, there is shown for purposes of illustrating this invention, a rotor hubY for a rotary winged aircraft mounted in a pylon I0 xed to the fuselage of the craft.

A member I2 is welded or otherwisel fixedly secured in the pylon I0, and receives a shaft member I4 having a pair of universal joint yokes I6 xed thereto. A driving sleeve I8 having spaced arms 20.is received over the shaft I4 and member I2 and is separated therefrom by needle bearings 22 and 24. The driving sleeve I8 is provided with a geared pinion 26 which meshes with a pinion 28 carried by a shaft 38 adapted to be driven by the engine or prime mover of the craft.

A stub shaft 32 having a pair of universal joint yokes 34 operably connected to the joint yokes I6 is provided in the central portion of the hub. An intermediate shell member 36 is positioned around the stub shaft 32 and is separated therefrom by ball and thrust bearings 38 and 48 respectively. The intermediate shell member 36 is provided with a plurality of spaced arms 42 adapted to engage the spaced arms 28 carried by the driving sleeve I8 to impart driving force from the sleeve I8 to the shell 36. The driving force is imparted through/balls 44 positioned in cooperating raceways 46 and 48 formed in the arms 20 and arms 42 respectively. The shell 36 is therefore driven at uniform velocity by the driving sleeve I8. ,y

A lower shell member 58 is positioned adjacentl and beneath the intermediate shell member 36. The intermediate and lower shell members 36 and 50 are formed with cooperating generally vertically disposed curved raceway segments 52 and 54 respectively adapted to receive balls 56 and 58 respectively. A plurality of rotary wing root segments 60 having spaced raceways 62 formed at their inner ends project through apertures in the intermediate and lower shell members 36 and 58 and engage the balls 56 and 58 carried by the shell members. The rotor wings are free to rll on the balls 56 and 58 to oscillate vertically. It will be observed that the raceways 52, 54, and 62 are so proportioned that the rotor wings oscillate about the center of the hub.

A wing attaching segment 64 having an aperture at one end iitted with needle bearings 66 is threaded or otherwise suitably secured to the wing root segment 68. The attaching segment 64 may be prevented from rotation with reference to the root segment 60 in any desired manner as by means of a bolt 68.

The angle of incidence of the rotor wing carried by the attaching segment 64 may be varied by rotating the lower shell with reference to the intermediate shell 36, thereby displacing the raceways 52 and 54 formed in the intermediate and lower shells laterally to'vary the effective vertical angle of the raceway 62 formed at the inner end of the wing root segment 60.

An upper shell member 10 is positioned to overlie the 'intermediate shell member 38, and is fixed to the lower shell member 58 in any desired manner as by means of bolts 12. A pair of ring gears 14 and 16 are carried byvand fixed to the upper shell member 18 and the intermediate shell member 36 respectively. 'I'he ring gears 14 and 16 have a different number of teeth, such, for example as seventy one and sixty nine, respectively. A pair of planet gears 18 positioned on opposite sides of the shaft 32 mesh with both of the ring gears 14 and 16 and with a centrally disposed pinion 80. 'I'he pinion 80 is provided at its upper end with a web 82 which carries an internally toothed sun gear 84.

A pinion 86 is fixed to the shaft 32 in any desired manner as by'a plunger 88 and a key 98. The pinion 86 meshes with a pair of interconnected pinion gears 92 which also mesh with the sun gear 84. Means including a friction connection 94 between the pinion 86 and the web 82 are provided to lock the pinion 86 to the pinion 80 and to the sun gear 84. The pinion 86 is of course restrained from rotation while the device is in operation, whereas the gears 14, 16, 18, 80 and 84 rotate with the shells 36 and 10. The pinions 92 are driven at a speed intermediate the speed of the sun gear 84 and the fixed gear 86.

Means including a cable 96, extending longitudinally through the hub, are provided to urge the pinion B6 into engagement with the web 82. When the cable 96 is actuated to operate the friction connection 94, the pinion 88 and sun gear 84 rotate at slower speed, or are held against rotation. The planet gears 18 then rotate backward with reference to the ring gears 14 and 16, thereby rotating the lower shell 50 with reference to the intermediate shell 36 to displace the generally vertically disposedy raceways 52 laterally -with reference to the raceways 54 to increase the pitch of the wing root segments 60 and therefore to increase the angle of the rotary wings fixed thereto.

A friction connection 98 is provided between the pinion gears 92 and the upper shell 18. When the cable 96 is released the pinion 80 and the sun gear 84 are released, whereupon the friction connection 98 tends to rotate the interconnected pinions 92 and the sun gear 84 ahead of the ring gears 14 and 16. The planet gears 18 are therefore urged to move ahead with reference to the ring gears 14 and 16, whereupon rotation is effected between the intermediate shell 36 and the lower shell 58 to displace the raceway segments 52 and 54 laterally to decrease the angles of incidence of the rotary wing segments operably connected thereto. f

.operating angles.

aicascs A centrifugally actuated stop member |03 is provided to engage the planet gears 13 to prevent the wing angle of incidence from being decreased below a predetermined limit while the craft is in flight. When the hub stops rotating after a landing has been effected, a spring |02 moves the centrifugally actuated stop |00 out of engagement with the planet gears 18 to permit further relative rotation between the intermediate shell 36 and the lower shell 50 to permit a reductionof the angle of incidence of the rotor wings to store energy to effect the next take-off.

'I'he hub, including the lower shell' 50, the intermediate shell 36 and the upper shell 10, may be turned about the yokes I6 and 34 of the universal joint to obtain longitudinal and lateral 4 control of the craft by means of a ring |04 positioned adjacent the lower shell 50, and sepa. rated therefrom by means of bearings |06. Any desired means may of course be employed to displace the ring |04 to effect the desired control, such, for example as that disclosed in Figures 12-to 1-5, or that disclosed in my copending application Serial No. 68,719, filed March 1'3, 1936.

It will be observed that the mechanism conc trollingvthe angle of incidence of the rotating Wings operates to permit the angle of incidence of the wings to be decreased to approximately zero while the craft ison the ground to permit driving of the rotating wings at a speed above the normal driving speed to store sufficient energy in the wings to facilitate a jump take-off. When the wings are rotating at the desired speed, the angle of incidence may be increased considerably above the normal operating angle to effect the take-olf, and when a desired altitude has been reached the angles of incidence of the wings may be progressively decreased to the normal The eentrifugally actuated stop member'operates to prevent the angles of incidence from being decreased below the normal operating angles while the craft is in flight. The angles of incidence of the wings may be increased considerably a'bove the' normal operating angles to interpose a braking action duringdescent, and after the craft has landed, the angles of incidence of the rotating wings, if desired, being decreased to permit the storing of energy in the rotating wings to effect the next jump take-off.

It will be understood of course that any desired means other than that shown may be employed to rotate the intermediate shell 36 with reference tothe lower shell 50 to vary the angles of incidence of the rotating wings. Such means may be actuated in any desired manner as by electrical or hydraulic means.

In the modified embodiment of the invention illustrated in Figures to 15, a two-part' hub only is employed.

In this embodiment of the invention a pylon |0| fixed to the fuselage of the aircraft houses a driving shaft, |03. The shaft |03 is guided and supported in the pylon |0| by bearings |05,

needle bearings |01, and thrust bearings |09. 'Ihe upper end of the shaft |03 is provided with universal joint yokes |||.which cooperate with oppositely disposed universal joint yokes ||3 to drive the hub at any desired angle to which it may be moved with reference-,to the pylon |0|.

An upper shell member ||5 is threaded or otherwise fastened toa stub shaft I |1 having the yokes ||3 at their lower end. The stub shaft ||1 is provided `with a flange ||9 which receives one endof a spring |2| which may take the form of a plurality of cone washers. The other end of the spring |2| bears on a flange |23 having a plurality of downwardly projected arms |25. As shown diagrammatically in Figure 11 the lower ends of the arms |25 are provided with bevelled segments |21 which engage correspondingly bevelled stops |29 carried by a lower shell member |3I, and stops |33 carried by the upper shell member ||5 to hold-the lower shell |3| into engagement with the upper shell ||5 and to rotate i the lower shell |3I with reference to the upper shell when the flange |23 is moved vertically. Stops |35 carried by the lower shell |3| are provided to engage the stops |33 carried by the upper he shell ||5 to limit relative rotation between shells and to prevent them from separating.

Rotary wing root segments |31 projecting through apertures in the upper and lower shells |25 and I3| are provided with generally vertically disposed raceways |39 to receive balls |4| which roll in generally vertically disposed raceway segments |43 and |45 formed in the upper and lower shell members ||5 and |3| respectively. As the flangel|23 is moved vertically the lower shellv |3| rotate's with reference to the upper shell ||5, thereby displacing the raceway segments u|43 and |45 laterally to vary the angle of inci`- dence of the rotary wings |41 fixed to the root segments |31.

An adjustable link |49 interconnects the lead' ing edge of the rotary wing |41 with the lower shell |31. Whenv power -is applied through the driving shaft |03 to drive the rotary wings |41, the wings |41 swing backwardly about the pivot connection |5| and exert tension on the link |49. 'I'he force transmitted through the link |49 rotates the lower shell |3| with reference to the upper shell ||5 to decrease the angle of incidence'of the wings |41.

Means are provided to lock the wings A| 41 in the substantially zero angle of incidence position to whichv they are urged when power is applied to rotate the wings.

A shaft |52 journalled in the lower shell |31 is provided with an eccentric |53 which engages in a slot |55 formed in the upper shell ||5 when the shells ||5 and |3| are moved to the zero angle of incidence position and the shaft |52 is rotated to move the eccentric |53 into the slot |55.

Means including a plunger |51, projecting through a ring |59 positioned adjacent the lower shell |3| and separated therefrom by bearings |6| are provided to engage a crank'l63 carried by the shaft |52 to rotate theshaft |52 to turn the eccentric |53 in the slot |55.

In the operation of this device, the link |49 interconnecting the leading edge of the wing |41 rotates the lower shell |3| with reference to the upper shell ||5 to decrease the angle of incidence of the wings |41 to substantially zero. The locking device including the eccentric |53 and the slot |55 hold the upper and lower shells ||5 and |3| from rotating. The angle of incidence of yit will be observed that a pair f links |62 and |64 engage the disc |59 on opposite sides thereof. A pair of cranks |65 and |61 journalled in a member |69 engage the links |62 and |64 respectively. A guiding member |1| fixed in the rings |59 slides in a pair of guides |13 xed with reference to the pylon |0|. Any suitable means may be employed to actuate the cranks |65 and |61 to move the ring |59 with reference to the pylon 0|.

When the cranks |65 and |61 are moved in opposite directions as illustrated in Figure 14, the guiding member |1| moves in the guides |13 as shown to control the craft longitudinally. When the cranks |65 and |61 are moved in the same directions, as illustrated in Figure 15 the guiding member |1| does not move in the guides |13, but rather the ring |59 is displaced angularly as illustrated to effect lateral control of the craft.

Figures 7, 8 and 9 illustratealternative embodiments of resilient means to urge the upper and lower shells ||5 and |3| to rotate with reference to each other to move the wings |41 to the high angle 'of incidence positions and also to hold them together.

In the embodiment illustrated in Figure 7, a plate |15 is provided with a plurality of apertures |11 adapted to receive fastening means to fix the plate to the upper shell ||5, and with apertures |19 to receive fastening means to x the plate 'to the lower shell |3I. A plurality of resilient strips |8| resiliently urge'the shells to rotate towardthe high angle position.

In the embodiment illustrated in Figure 8, a pair` of overlapping clamps |93 and |85 are designed to be fixed to the upper and lower shells ||5 and |3| respectively. Resilient material |81 molded or otherwise secured to the clamps |83 and |95 urge the upper and lower shells ||5 and |3| to rotate toward the high angleposition. A

ball |89 fixed to the clamp |85 which engages the lower shell |3| is adapted to receiveone end of the link |49 interconnecting the lower shell of the hub and the leading edge of the wing |41.

The embodiment illustrated in Figure A9 is gen.- erally similar to that illustrated in Figure 8; however, it will be observed that a clamp |9| which engages the upper shell |5 is positioned to overlie the clamp |93 engaging the lower shell. In this embodiment the ball |95 which receives -the link |49, projects through the resilient material |91 and is fixed to the clamp |93 fixed to the lower shell |3|.

Referring to Figure 10 it will be observed that a resilient bushing |99 is fitted in the end.of the leading edge of the wing |41 to receive the connection to the link |49 to interpose a resilient support between the link |49 and the wing |41.

Referring now to Figure 5, it will be observed that a pylon 200 fixed to the fuselage of the aircraft is provided at its upper end with a stop member 202. The stop member 202 cooperates with another stop member 204 carried by a-hub supporting member 206 to ehgag'ewsiring l208 or other resilient member therebetwenffjn link 2| 0 connected to the supporting member206'is operably connected to the wing angle of incidence control mechanism to vary the angle'of incidence/of the rotating wings when the craft is subjected to unnatural forces, such, for example, as air bumps while in flight; The operation of the wing angle of incidence control mechanism is thus influenced by the forces to which the craft is subjected to damp out or minimize the influence of such undesirable forces.

While the invention has been described with particular reference toa limited number of desirable embodiments, it is to be understood that various constructional changes may be made without departing from the spirit of the invention as defined by the following claims.'

I claim:

1. In a hub to engage rotatable aircraft wings adapted to rotate at an angle of incidence and to oscillate vertically, a two-part rotatable shell, means engaging both parts of said shell to connect the wings to the hub, means to cause rotation between the two parts of the shell to change the angle of incidence of the wings, and means engaging both parts of the rotatable shell to enable the wings to oscillate vertically about the center of the hub.

2. In 4a hub to engage rotatable aircraft wings adapted to rotate at an angle of incidence, a rotatable shell including a plurality of rotatable parts, bearing surfaces in two adjacent parts, means engaging said bearing surfaces'to connect the wings to the hub, means to cause rotation between said parts to change the angle of incidence of the wings, and means'engaging said bearing surfaces to enable the wings to oscillate vertically about the center of the hub.

3. In a hub to engage rotatable vertically oscillatable aircraft wings adapted to rotate at an angle of incidence, a rotatable shell including a plurality of rotatable parts, means engaging a plurality of said parts tov connect the wings to the hub in such manner that the wings may oscillate vertically about the center of the hub, means to cause rotation between said parts to change the angle of incidence of the wings, and means to prevent the angle of incidence of the wings from decreasing below a predetermined degree while the craft is in flight.

4. In a hub for rotatable aircraft wings adapted to rotate at an angle of incidence, a rotatable shell including two spaced sections having bearing surfaces therein, means engaging said bearing surfaces to connect the wings to the hub so that the wings may oscillate vertically about the center of the hub, and means to displace said sections to `change the angle of incidence of the wings. s

5. In a hub for rotatable aircraft wings adapted to rotate at an angle of incidence and to oscillate `ing sections therein, means engaging said bearing sections to connect the wings to the hub, means including planetary gears to displace said sections to change the angle of Vincidence of the wings, and manually operable clutching means to effect operation of said planetary gears to effect.

a change in the angle of incidence of said wings. 7. A hub for a rotary winged aircraft having wings adapted to rotate at an angle of incidence :comprising a rotatable shell including vertically spaced sections having bearing surfaces therein adapted to engage the rotatable wings, means engaging said bearing surfaces to varyv the angle of incidence of the wings when said sections are rotationally d'spla'ced, and power operated means including planetary gearing driven by the .rotatable shell to rotationally displace said sections.

8. A hub for a rotary winged aircraft having Wings adapted to rotate at an angle of incidence comprising a rotatable shell including vertically spaced sections having bearing members therein adapted to engage the rotatable wings, means engaging said bearing members to vary the angle of incidence of the wings when said sections are rotationally displaced, ring gears carried by each of said sections, planetary gearing operably con- "nected to the ring gears, and vclutching means planetary gearing o, .,:rably connected to the ring gears, and clutching means adapted to engage said planetary gearing to effect relative rotation between said ring gears to vary the angle of incldence of the rotatable wings.

'10. A hub`for a rotary winged aircraft having wings adapted to rotate at an angle of incidence and free to oscillate vertically comprising a rotatable shell including vertically spaced sections adapted to engage the rotatable wings, means engaging said sections to vary the angle of incidence of the wings when said sections are rotationally displaced, ring gears having different numbers of teeth operably connected to each of said sections, planetary gearing operably connected to the ring gears, clutching means adapted to engage said planetary gearing to veffect relative rotation between said ring gears to vary the angle of incidence of the rotatable wings, speed responsive stop means adapted to engage the planetary gearing to prevent the angle of incidence of the wings from being decreased below a predetermined angle while the craft is in flight, and manually operable means to actuate said clutching means to vary the angle of incidence of the wings.

11. In a hub for a rotary winged aircraft having wings adapted to rotate at an angle of incidence and to oscillate vertically, a rotatable shell including spaced sections, means to vary theangle of incidence of the wings upon rotational displacement of the spaced sections, yielding means urging the spaced sections'in the angle increasing direction, locking means to hold the sections in a low angle position, and manually operable means to release said locking means.

12. In a hub for a rotary winged aircraft having wings adapted to rotate at an angle of incidence and tooscillate vertically, a rotatable shell including spaced sections, means to vary the angle of incidence of the wings upon rotational displacement of the spaced sections, locking means to hold the `sections in` a fixed angle position, manually operable means to release said locking means, and yielding means to urge the spaced sections in a direction to vary the angle of incidence of the wings when said locking means is released.

13. In a hub for a rotary winged aircraft having a fuselage and wings adapted to rotate at an angle of incidence, a rotatable shell including spaced sections having cooperating bearing surfaces, means to vary the angle of incidence of the Wings upon rotational displacement of the spaced sections, means to rotationally displace said sections to vary the angle of incidence of the wings, and yielding means interposed between the hub and the fuselage to influence the operation of the last named means when the aircraft is subjected to unnatural forces.

14. A hub for a rotary winged aircraft having wings adapted to oscillate vertically independently about a common point at the center of the hub comprising a generally vertically disposed driving member, a rotatable shell, universal driving means between the driving member and the rotatable shell, and means to tilt the rotatable shell with reference to the driving means.

15. A hub for a rotary Winged aircraft comprising a generally vertically disposed driving member, a rotatable shell, universal driving means between the driving member and the rotatable shell, means to tilt the rotatable shell with reference to-the driving means, a plurality of wing root segments extending into the rotatable shell and adapted to oscillate vertically with reference thereto, and means to vary the angles between the wing root segments and the rotatabl'e shell.

16. A hub for a rotary winged aircraft comprising a generally vertically disposed driving member, a rotatable shell.' universal driving means between the driving member and the rotatable shell, a plurality of wing root segments extending into the rotatable shell, means including generally vertically disposed raceways between the Wing root segments and the rotatable shell and anti-friction means in the raceways to permit vertical oscillation of the wing segments about the center of the hub, and means to vary the angles between the wing segments .and the rotatable shell.

i ing vertically oscillable rotatable wings mounted to oscillate independently about a common point at the center of the hub, a rotatable shell, means to drive the rotatable shell, means engaging the rotatable shell to vary the longitudinal and the lateral angles between the shell and the driving means to directionally control the aircraft, and means including spaced motion imparting means to move the shell to vary said longitudinal and lateral angles to directionally control the craft.

GEORGE S. SCHAIRER. 

